MacBook Clamshell Mode Not Working? 11 Easy Solutions

Clamshell mode on MacBooks is useful, especially when multitasking and performing heavy tasks. But how do you feel if this mode does not work on your Mac? It’s quite frustrating, isn’t it?

Undoubtedly, it’s very frustrating since it wastes time and attention. It mainly happens when you have incompatible display settings saved on your Mac. Or there could be several other reasons.

In this article, I’ve discussed why MacBook clamshell mode not working and how to fix it. Surely after reading this, you can operate your Mac in clamshell mode. So let’s get started.

11 Reasons And Fixes Why MacBook Clamshell Mode Does Not Work 

Below is why MacBook Clamshell won’t work with your Mac. 

I’ve listed its solution for each reason, so if you think any reason is relevant, follow it up with its fix. So let’s go:

1. Incompatible Mac Model

Taking a closer look at this main reason is crucial before moving on to any other because Clamshell mode is only compatible with some specific Mac models.

So, if you cannot operate Clamshell mode, chances are your Mac doesn’t support this mode.

Below is the list of Mac models that supports Clamshell mode:

• 13-inch MacBook Pro (2016 or later) 
• MacBook Air (2018 or later) 
• Mac Mini (2018 or later) 
• iMac (2017 or later)

So, if you don’t have any of these models, sorry to say you can’t operate Clamshell mode. 

But if you own any of these models and cannot run clamshell mode, there must be other reasons for the issue.

2. Incompatible Display Settings

This is the main cause of this issue, and about 60% of people are affected by it. Remember, Clamshell mode won’t work until you have compatible display settings saved in your Mac.

When your Mac’s display settings don’t match the external display, the issue comes up, and Clamshell mode fails to run.

So, if you see a blank screen, flickering, incorrect resolution, and no display output in Clamshell mode, it’s because of the incompatible display settings.

To fix this problem, apply the external display resolution and aspect ratio compatible with Clamshell mode to your external display.

For this purpose, follow these steps:

• Click on the Apple logo from the top left corner of your screen.
• Launch System Preferences and go to Displays.
• Here you have two options, a Built-in display and an external display. Go with the external display.
• Under this section, look for the scaled option and click on it.
• Here you’ll see a list of resolutions. Select the one that matches your external display.

After setting up the display settings, your Clamshell mode should run. But if the issue persists, move on to the next reasons.

3. Faulty Accessories

Faulty accessories are also the leading cause of Clamshell mode not working. This is because, for Clamshell mode, it’s important to have the right accessories; if any of them is faulty, it will not work.

Clamshell mode accessories include an external monitor, thunderbolt cable or thunderbolt to HDMI adapter, external mouse, and keyboard. So, you need to double-check the accessories before operating your Mac in Clamshell mode.

But according to my experience, the issue mainly occurs in the HDMI cable and HDMI adapter. So, keep an eye on these two things, set them up correctly, and then try again.

There is a 15% chance that the Clamshell mode will start working after this fix.

4. Sleeping Might Be Enabled

It’s also possible to say that this cause contributes 5% to the clamshell mode issue. Also, when the sleep feature is enabled, it will cause Mac to overheat in Clamshell mode.

Due to this reason, Clamshell mode will automatically turn off or will not work to prevent any serious loss of hardware.

So, it’s important to turn off the sleep feature on the Mac to avoid overheating and to turn on Clamshell mode to work properly. To turn off this feature, follow these simple steps:

1. Go to System Preferences

2. Click on Battery.

3. Select Power adapter.

4. In this section, move the slider of “Turn display Off after” to never.
5. Also, enable the option “Prevent your Mac from sleeping.”

5. Fishy Apps

You may or may not believe this, but some fishy apps can prevent Clamshell mode from functioning.

This is because some apps or software may not support the Clamshell mode or any function in this mode. So, you must check for such apps and disable or uninstall them.

6. Low Battery

The clamshell mode doesn’t work in the low battery mode because of the power management settings of the Mac.

Remember, in the Clamshell mode, the lid of your Mac is closed, due to which power is more consumed. 

As a result, when your Mac is in power-saving mode, there is not enough power to operate Clamshell mode, and it will automatically turn off or stop working.

So, to prevent this issue, you need to fully charge your Mac before entering clamshell mode. I recommend plugging in the charging cable during this mode to avoid this battery headache.

7. Laptop Monitor Connection Problem

Sometimes, there might be a connection problem between the external monitor and Mac, due to which this issue arises.

Several factors contribute to this, including your computer’s graphics, other hardware, and your monitor.

So, in such situations, you need to disconnect the HDMI cable and the monitor’s power cable for 5-20 seconds. By doing so, all the monitor’s settings will reset.

Also, it will solve the other software conflicts between the system and monitor that could help to solve the issue. In short, it acts as a restart of the device.

8. Dirty USB Ports

Sometimes, your Mac USB ports might be clogged with dirt that could prevent the HDMI cable from transmitting proper signals. Due to this, the Clamshell mode doesn’t work properly.

So, you need to clean the USB ports to solve the issue. But be gentle on your ports and don’t use any sharp instrument that could lead to a serious loss.

9. MacBook Might Not Be Plugged In

It’s also a major cause of the issue because when the Mac is not plugged in, it will go to sleep mode, and Clamshell mode won’t run to avoid overheating issues.

So, it’s important for you to just plug in your Mac to keep it fully charged and prevent it from sleeping in Clamshell mode.

10. Software Or Hardware Problem

Sometimes, there might be a software bug or conflict that could lead to the Clamshell mode failure. In such cases, you need to restart your Mac to solve these issues.

Also, there might be a hardware problem, or the system updates could cause it. So, restart your Mac in such situations to solve all these issues.

11. Software Glitches

Another possible cause of the Clamshell mode not working is the software glitches which mostly occur in the macOS. To deal with such issues, Apple brings updates in the macOS which can solve these issues.

So, if all the above fixes don’t work, update your macOS to see if the clamshell mode works.

Things To Consider When Fixing MacBook Clamshell Mode Not Working Issue

To prevent any serious loss, the following things must be taken into account when fixing the Clamshell, not working issue on Mac:

• Always use a soft thing to clean your USB-C ports and avoid sharp things like a knife.
• Buy high-quality accessories like HDMI cables and keyboards, etc.
• Make sure you save your work before updating or restarting your Mac.

Frequently Asked Questions (FAQs)

Final Words

The whole article concluded that the MacBook Clamshell mode is not working because of the incompatible display settings saved on your Mac.

Hopefully, now you should know all about the Clamshell mode issues and how to fix them.